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cromioclavicular joint disloca-tions are common injuries that aregenerally classified on routine ra-

diography. However, classifying these lesionson MR imaging is different for two reasons.First, age-related acromioclavicular jointchanges are almost universal in adults and, insome cases, cannot be reliably differentiatedfrom acromioclavicular ligament sprains.Second, the supine position of the patient be-ing scanned changes the relationship of thescapula to the clavicle and reduces theamount of gravity-assisted displacement clas-sically used in radiographic classificationschemes. The appearances of the surroundingsoft tissues, rather than of the acromioclavic-ular joint itself, are useful in classification ofacromioclavicular joint injuries and can beprovided by MR imaging. In particular, theintegrity of the coracoclavicular ligamentplays a central role in this classification.

Anatomy

The coracoclavicular ligament is composedof the conoid and trapezoid parts (ligaments).The trapezoid ligament lies laterally to theconoid ligament and is separated from it by fat

or a bursa. The two parts form a

V

with an open-ing facing posterosuperiorly [1] (Fig. 1A).

The trapezoid ligament is quadrilateral. It isattached to the superior aspect of the anteriorborder of the base of the coracoid process andextends in a posterosuperolateral, roughlystraight course to the trapezoid line in the infe-rior surface of the clavicle (Figs. 1B and 1C).The trapezoid ligament is the primary restraintagainst posterior clavicular displacement [2]and also provides resistance against anterior,superior, and inferior forces. Individual fibersof the ligament are recognizable on 30-mm-thick T1-weighted images in the coronalplane because they are on anatomic sections(Figs. 1D and 1E).

The conoid ligament is triangular with aninferior apex that is attached to the medialborder at the base of the coracoid process justmedially and posteriorly to the origin of thetrapezoid ligament and laterally to the scapu-lar notch. The conoid ligament courses in aspiraling fashion, almost vertically in a supe-rior direction. Its base attaches to the conoidtubercle in the inferior surface of the clavicleand, for a short distance, in a line proceedingmedially from it. The conoid tubercle is lo-cated at the junction of the lateral and middle

thirds of the clavicle [1]. The conoid ligamentfunctions as the main restraint against ante-rior and superior displacement of the clavicle,as well as against anterior and superior rota-tion of the bone [3]. The individual fibers ofthe conoid ligament are difficult to distin-guish on MR images (Fig. 1D).

Two muscles are attached to the scapularspine and acromion. The trapezius muscle in-serts on the superior aspect of the scapularspine and acromion. The deltoid muscle has fi-bers originating from the inferolateral marginof the scapular spine and acromion.

Acromioclavicular Dislocation

Acromioclavicular dislocation is a commoninjury, occurring in greater than 10% of shoul-der injuries. Most of these injuries occur whenthe subject falls and strikes the adducted shoul-der against the ground [4]. The scapula ispushed downward and forward relative to theclavicle. This action results in stretching andtensile failure of the acromioclavicular liga-ments, coracoclavicular ligament, and trapeziusmuscle insertion, in that order. Biomechanicalstudies have shown that the acromioclavicu-lar ligaments contribute to a greater amount

MR Imaging Appearance and Classification ofAcromioclavicular Joint Injury

Gregory E. Antonio

1,2

, Jae Hyun Cho

1

, Christine B. Chung

1

, Debra J. Trudell

1

, Donald Resnick

1

Received June 24, 2002; accepted after revision September 10, 2002.

Presented at the annual meeting of the American Roentgen Ray Society, Atlanta, April–May 2002.

1

Department of Radiology, Veterans Administration Medical Center, 3350 La Jolla Village Dr., San Diego, CA 92161.

2

Present address: Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Shatin, Hong Kong. Address correspondence to G. E. Antonio.

AJR

2003;180:1103–1110 0361–803X/03/1804–1103 © American Roentgen Ray Society

Pictorial Essay

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A B

C D

E

Fig. 1.—Appearance of normal shoulder.A, Drawing shows normal shoulder. Gap between conoid and trapezoid parts hasbeen exaggerated in this and the subsequent drawings. Co = conoid ligament, Tr =trapezoid ligament, CA = coracoacromial ligament, CP = coracoid process. B, T1-weighted oblique sagittal MR image (TR/TE, 600/22) of shoulder shows trap-ezoid part of coracoclavicular ligament (arrow) running posterosuperiorly frombase of coracoid process (CP) to undersurface of clavicle (Cl). A = acromion. C, Photograph of oblique sagittal anatomic section corresponding to B shows co-racoclavicular ligament (arrow) running from base of coracoid process (CP) to un-dersurface of clavicle (Cl).D, T1-weighted oblique coronal MR arthrogram (600/22) shows coracoclavicularligament in left shoulder. Conical fibers (arrowheads) of conoid ligament insertinto conoid tubercle, compared with more lateral trapezoid ligament fibers(arrow), which run parallel. Cl = clavicle, D = deltoid muscle, GHJ = glenohumeraljoint distended with contrast material. E, Photograph shows oblique coronal anatomic section of coracoclavicular liga-ment of left shoulder, corresponding to D. Conical fibers (arrowheads) of conoidligament insert onto conoid tubercle, compared with more lateral trapezoid liga-ment fibers (arrow), which run parallel. Cl = clavicle, D = deltoid muscle, H = hu-meral head.

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of restraint at small degrees of acromioclavicu-lar joint distraction, whereas the coracoclavicu-lar ligament is the main restraint at largerdegrees of acromioclavicular joint distraction[2]. The widely used Rockwood classificationof acromioclavicular joint injuries is based onthis mechanism of injury [4].

MR Imaging Findings

Our clinical images (Figs. 2–7) were ob-tained with 1.5-T MR scanners, using a stan-dard shoulder coil. Oblique dual-echo coronal,oblique T2-weighted fat-saturated sagittal, andaxial intermediate-weighted MR images werealways obtained; some patients underwent ad-ditional gadolinium-enhanced T1-weightedimaging. Whereas the anatomy of the coraco-clavicular ligament is best seen on T1-weighted images because of their inherentlyhigh signal-to-noise ratio (Fig. 1B), structures inT2-weighted fat-saturated images tend to be in-

distinct, although continuous ligamentous fibersare identified with some effort. With injury,edematous fluid around the coracoclavicularligament makes the fibers more evident onT2-weighted fat-saturated (Fig. 3D) or interme-diate-weighted MR images (Fig. 3E). Con-versely, T1-weighted images are difficult tointerpret because of the edematous fluid andblood products (Fig. 3C). Although not essentialfor diagnosis, IV gadolinium can delineate theextent and path of the soft-tissue damage exquis-itely (Fig. 3F).

Type I Acromioclavicular Joint Injury

In a type I injury, a mild force at the acro-mion produces a sprain in the acromioclavicularligament, but the coracoclavicular ligaments arenot involved. In our experience, there are nospecific MR imaging signs for this type of in-jury because signal abnormalities are commonin the acromioclavicular joint of adult patients.

Type II Acromioclavicular Joint Injury

In a type II injury, a moderate force results inrupture of the acromioclavicular ligament (Figs.2A and 2B). The coracoclavicular ligament issprained, resulting in edema (Fig. 2C). Continu-ity of the coracoclavicular ligament fibers ismaintained. There is also marrow edema in thelateral ends of the clavicle and acromion.

Type III Acromioclavicular Joint Injury

In a type III injury, a severe force results incomplete acromioclavicular joint dislocation(Figs. 3A, 3B, and 3F). The coracoclavicularligament is completely ruptured. Blood andfluid are seen in the coracoclavicular inter-space. Images with long TRs are valuable be-cause blood and fluid tend to obscure the fibersof the coracoclavicular ligament on short-TRimages (Figs. 3C–3E). The deltoid and trape-zius muscles may be detached from the distalend of the clavicle (Fig. 3G).

A B

C

Fig. 2.—Type II acromioclavicular joint injury.A, Drawing shows type II acromioclavicular joint injury. Acromioclavicular joint is disrupted;coracoclavicular ligaments are sprained but intact. Superior displacement of clavicle is mini-mal because of intact coracoclavicular ligaments.B, Oblique sagittal T2-weighted fat-saturated MR image (TR/TE, 3000/99.9) of shoulder in 39-year-old woman shows type II acromioclavicular joint injury. Acromioclavicular joint capsuleand superior and inferior acromioclavicular ligaments (arrow) are disrupted. Note stripping ofclavicular periosteum (arrowheads) with inferior acromioclavicular ligament disruption. Highsignal in marrow of clavicle (Cl) and acromion (A) indicates edema. H = humeral head.C, Oblique sagittal T2-weighted fat-saturated MR image (3000/99.9) shows same patient as in Bbut in more medial view. High signal in region of coracoclavicular ligament (arrow) indicatesedema due to injury. Cl = clavicle, A = acromion, CP = coracoid process.

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A fracture of the coracoid process medial tothe site of attachment of the coracoclavicularligament associated with an acromioclavicularjoint dislocation has the same implications as aninjury classified by Rockwood [4] as type III orhigher. This fracture should be suspected in allacromioclavicular joint dislocations in the firstthree decades of life [5] and may be missed onradiographic series in which an axillary view isnot included. Even with the inclusion of this

view, the fracture may still be difficult to recog-nize because there may not be any displacementof the fracture (Fig. 3H).

Type IV Acromioclavicular Joint Injury

In a type IV injury, the distal end of the clavi-cle is posteriorly dislocated as the scapula isdriven anteroinferiorly (Fig. 4A). Therefore, thisinjury is more appropriately named anterior dis-location of the scapula [6]. A frontal radiograph

will not show any vertical displacement at theacromioclavicular joint (Fig. 4B). Axial imag-ing is the optimal method and allows correctclassification (Fig. 4C). The lateral end of theclavicle may be driven posteriorly through thetrapezius muscle (Fig. 4D). Bipolar dislocation,in which both the acromioclavicular and sterno-clavicular joints are dislocated, should be keptin mind in this type of acromioclavicular jointinjury [7].

A B

C D

Fig. 3.—Type III acromioclavicular joint injury.A, Drawing of type III acromioclavicular joint injury shows acromioclavicular and coracoclavicular ligaments disrupted, effectively releasing major linkage mechanism ofscapula to body. Acromioclavicular separation is moderate. Plane of dissection can be seen beginning laterally at acromioclavicular joint and running medially throughtrapezoid and conoid ligaments. Coracoacromial ligament is below this plane.B, Coronal T1-weighted MR image (TR/TE, 566/16) of coracoclavicular region shows type III acromioclavicular joint injury in 70-year-old man. Note disruption of acromio-clavicular ligaments (arrow) and intervening hematoma. Cl = clavicle, A = acromion, CP = coracoid process, H = humerus.C, Oblique coronal T1-weighted MR image (566/16) of coracoclavicular region shows type III acromioclavicular joint dislocation (same patient as in B). Note low-signal-intensity mass (arrows) obscuring coracoclavicular ligament. Cl = clavicle, CP = coracoid process.D, Coronal T2-weighted fat-saturated MR image (3250/96) shows type III acromioclavicular joint dislocation (same patient as in B). Note disruption of all ligamentous fibers(arrow) and hematoma around acromioclavicular joint. Cl = clavicle, CP = coracoid process.(Fig. 3 continues on next page)

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Type V Acromioclavicular Joint Injury

Type V acromioclavicular joint injury (Figs.5A and 5B) is an exaggeration of the type IIIinjury. The trapezius and deltoid muscle at-tachments on the clavicle and acromion are

completely stripped (Figs. 5C–5E). The scapulahas therefore lost all its major suspensory sup-ports and droops inferiorly. The combination ofloss of all the inferior soft-tissue attachments inthe distal clavicle and an unopposed pull by the

sternocleidomastoid muscle further accentuatesthe acromioclavicular joint displacement, result-ing in the classic and grotesque superior displace-ment of the distal end of the clavicle. The claviclemay even penetrate the trapezius muscle.

E F

G H

Fig. 3.—(continued) Type III acromioclavicular joint injury.E, Coronal intermediate-signal MR image (2200/48) shows type III acromioclavicular joint dislocation (same patient as in B). Note heterogeneous collection around dis-rupted (curly) ligamentous fibers (arrow). Cl = clavicle, CP = coracoid process.F, Oblique coronal enhanced fat-saturated T1-weighted MR image (466/19) shows type III acromioclavicular joint dislocation in 35-year-old man. Note dissection planebeginning at disrupted acromioclavicular joint (large arrow), extending medially (arrowheads), and ending medially to disrupted coracoclavicular ligament (small arrows).Cl = clavicle, A = acromion, CP = coracoid process, H = humerus.G, Sagittal fat-saturated T2-weighted MR image (2000/90) shows type III acromioclavicular joint dislocation (same patient as in F). Note rupture of coracoclavicular liga-ment, with its fibers mixed with blood and fluid (arrowheads). Tear extends to involve deltoid muscle. Anterior fibers of deltoid muscle (arrow) from clavicle (Cl) are partiallytorn. CP = coracoid process.H, Oblique sagittal intermediate-signal MR image (2200/46) of 47-year-old man shows fracture of coracoid process at its base (arrowheads), acromioclavicular joint dislocation, and intactcoracoclavicular ligament (arrow). This injury is also classified as type III when associated with acromioclavicular joint dislocation. Cl = clavicle, CP = coracoid process, A = acromion.

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Type VI Acromioclavicular Joint Injury

Type VI acromioclavicular joint injury is arare injury caused by a different mechanism.The injury is thought to be due to a severe di-rect force on the superior surface of the distalclavicle with abduction of the humerus andretraction of the scapular at the same time.As a result, the lateral end of the clavicle

rests inferiorly to the acromion or coracoidprocess.

Prior Acromioclavicular Joint Injury

The telltale sign of a prior, often remoteacromioclavicular joint injury is calcificationor ossification of the coracoclavicular liga-ment (Figs. 6 and 7).

Discussion

The central role of the coracoclavicularligament in the classification of acromioclav-icular joint injury is that it serves as a divid-ing line between operative and nonoperativetherapy. Rockwood types I and II acromio-clavicular injuries are treated conservatively[4]. Types IV, V, and VI injuries are surgically

A B

C

Fig. 4.—Type IV acromioclavicular joint injury.A, Drawing shows type IV acromioclavicular joint injury. Acromioclavicular and coracoclavicular ligaments are disrupted, and lateral end of clavicle is posteriorly dis-placed. Clavicular displacement is in horizontal plane. Thus, frontal view may underestimate amount of acromioclavicular joint displacement. B, Frontal radiograph shows type IV acromioclavicular joint dislocation in 27-year-old man. Note widening of acromioclavicular joint with no vertical displacement, sug-gesting type II dislocation. Cl = clavicle, A = acromion.C, Axial intermediate-weighted MR image (TR/TE, 3000/18) shows type IV acromioclavicular joint dislocation (same patient as in B). Note posterior dislocation (arrow) oflateral end of clavicle (Cl) at acromioclavicular joint. A = acromion.D, Sagittal intermediate-weighted MR image (3000/18) shows type IV acromioclavicular joint dislocation (same patient as in B). Note tear of coracoclavicular ligament(arrowheads) and deltoid fibers (arrows). Note posterior displacement of lateral end of clavicle (Cl), which is penetrating trapezius muscle (asterisk). A = acromion, CP =coracoid process.

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A B

C D

E

Fig. 5.—Type V acromioclavicular joint injury.A, Drawing shows type V acromioclavicular joint injury. Acromioclavicular andcoracoclavicular ligaments are disrupted, effectively releasing major linkagemechanism of scapula to body. In addition, accessory suspensor (trapezius mus-cle attachment) is also disrupted. Acromioclavicular separation is marked.B, Coronal fat-saturated T1-weighted MR image (TR/TE, 816/16) shows type V acro-mioclavicular joint dislocation in 43-year-old man. Note rupture of acromioclavicularligaments (arrowheads), hematoma, and approximately 100% shaft-width disloca-tion. This dislocation may represent type III or type V injury. Cl = clavicle, A = acro-mion, CP = coracoid process, H = humerus.C, Oblique sagittal fat-saturated T1-weighted gadolinium-enhanced MR image(600/16) shows type V acromioclavicular joint dislocation (same patient as in B).Note stripping of deltoid muscle (arrows) from anterior aspect of clavicle (Cl) andrupture of coracoclavicular ligament (arrowheads). CP = coracoid process.D, Axial fat-saturated T1-weighted MR image (750/15) shows type V acromioclav-icular joint dislocation (same patient as in B). Note rupture and associated hem-orrhage of trapezius muscle insertion (arrowheads) on acromion (A) andscapular spine. E, Oblique sagittal fat-saturated T1-weighted gadolinium-enhanced MR image(600/16) of acromion (A) and scapular spine shows type V acromioclavicular jointdislocation (same patient as in B). Note rupture of trapezius muscle insertion(arrowheads). H = humeral head.

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treated. The treatment choice for Rockwoodtype III injury is controversial. Type III inju-ries, which account for approximately 40%of acromioclavicular injures [4], are not wellevaluated on radiographs, even with addi-tional weighted views [8]. MR imaging,however, provides exquisite evaluation of theadjacent soft-tissue structures. Knowledge ofcoracoclavicular ligament anatomy and ofthe appearance of acromioclavicular injuryon MR imaging aids physicians in determin-ing the extent of the injury and the type oftreatment that is most appropriate.

The goal of treatment is to reduce the liga-ments in an anatomic manner to reproducenormal ligamentous mechanics and preventacromioclavicular joint degeneration. Thereare many variations in the surgical approach[3], but the contemporary focus is to stabilizethe scapula, using some form of fusion or re-construction at the coracoclavicular level. Pre-cise reconstruction is important to reduce pain,to improve range of motion of the acromio-clavicular joint, and to reduce the possibilityand extent of secondary joint degeneration.Failure of treatment may result in chronic inca-pacitating pain. With increasing expectationsfor improved cosmesis and minimal morbidity,

arthroscopic reconstruction may play a promi-nent role in future treatment. This procedurewould require the precise definition of the in-jury afforded by MR imaging performed be-fore surgery. Presently, no defined role existsfor MR imaging in acromioclavicular joint in-jury. Patients with type III or more serious in-jury would benefit from the additionalinformation obtained on MR imaging, particu-larly when there is a choice among conserva-tive, arthroscopic, and open surgical treatment.

Conclusion

MR imaging provides exquisite visualiza-tion of the soft-tissue structures of the shoul-der girdle. The sequential manner of damageto these supporting structures in injuries ofthe acromioclavicular joint results in the clin-ical and radiographic classification systemsthat are currently in use. This soft-tissue in-jury to the supporting structures is well seenwith MR imaging, allowing a direct methodof classification rather than relying on mea-surements afforded by routine radiography.The coracoclavicular ligament plays a centralrole in maintaining acromioclavicular jointstability, and its appearance should be care-

fully scrutinized in all patients undergoingshoulder MR imaging.

References

1. Williams PL, Bannister LH, Warwick R, et al. Theanatomical basis of medicine and surgery. In: GrayH, Pick TP, Howden R, eds.

Gray’s anatomy

, 38thed. London: Churchill Livingston,

1995

:619–6222. Lee KW, Debski RE, Chen CH, Woo SL, Fu FH.

Functional evaluation of the ligaments at the acromio-clavicular joint during anteroposterior and superoinfe-rior translation.

Am J Sports Med

1997

; 25:858–862 3. Fukuda K, Craig EV, An KN, Cofield RH, Chao

EY. Biomechanical study of the ligamentous sys-tem of the acromioclavicular joint.

J Bone JointSurg Am

1986

;68:434–440 4. Buckholz RW, Heckman JD.

Rockwood andGreen’s fracture in adults

, 5th ed. Philadelphia:Lippincott Williams & Wilkins,

2001

:1210–12445. Bernard TN Jr, Brunet ME, Haddad RJ Jr. Frac-

tured coracoid process in acromioclavicular dislo-cations: report of four cases and review of theliterature.

Clin Orthop

1983

;175:227–232 6. Hastings DE, Horne JG. Anterior dislocation of the

acromioclavicular joint.

Injury

1979

;10:285–288 7. Sanders JO, Lyons FA, Rockwood CA Jr. Man-

agement of dislocations of both ends of the clavi-cle.

J Bone Joint Surg Am

1990

;72:399–402 8. Bossart PJ, Joyce SM, Manaster BJ, Packer SM.

Lack of efficacy of “weighted” radiographs in di-agnosing acute acromioclavicular separation.

AnnEmerg Med

1988

;17:20–24

Fig. 6.—Oblique coronal gradient-echo MR image (500/15; flip angle, 30°) in 54-year-old manshows ossification of trapezoid (arrow) and conoid ligaments due to previous acromioclavicu-lar joint injury. Cl = clavicle, CP = coracoid process.

Fig. 7.—Radiograph of 49-year-old man shows coracoclavicular liga-mentous ossification (arrows) (similar to that in Figure 6) from previousacromioclavicular dislocation

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05/

27/1

8 fr

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P ad

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9.14

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This article has been cited by:

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2. K. Aaron Shaw, John Synovec, Josef Eichinger, Christopher J. Tucker, Jason A. Grassbaugh, Stephen A. Parada. 2018. Stressradiographs for evaluating acromioclavicular joint separations in an active-duty patient population: What have we learned?. Journalof Orthopaedics 15:1, 159-163. [Crossref]

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5. Jacob D. Gorbaty, Jason E. Hsu, Albert O. Gee. 2017. Classifications in Brief: Rockwood Classification of Acromioclavicular JointSeparations. Clinical Orthopaedics and Related Research® 475:1, 283-287. [Crossref]

6. Adam Greenspan, Javier Beltran. Obere Extremit?t I 105-158. [Crossref]7. Mark Tauber, Achim Hedtmann, Hanns Fett. Erkrankungen und Verletzungen des Akromio- und Sternoklavikulargelenks

273-308. [Crossref]8. Maurice Balke. 2016. Diagnosis and Treatment of Acute Acromioclavicular Joint Injuries. Archives of Trauma Research 6:2. .

[Crossref]9. P. Loriaut, L. Casabianca, J. Alkhaili, B. Dallaudière, E. Desportes, R. Rousseau, P. Massin, P. Boyer. 2015. Évaluation des résultats

cliniques et de l’IRM du traitement arthroscopique des disjonctions acromio-claviculaires aiguës traitées par double bouton. Revuede Chirurgie Orthopédique et Traumatologique 101:8, 602-609. [Crossref]

10. P. Loriaut, L. Casabianca, J. Alkhaili, B. Dallaudière, E. Desportes, R. Rousseau, P. Massin, P. Boyer. 2015. Arthroscopic treatmentof acute acromioclavicular dislocations using a double button device: Clinical and MRI results. Orthopaedics & Traumatology:Surgery & Research 101:8, 895-901. [Crossref]

11. Maria Valencia Mora, Jorge Diaz Heredia, Raquel Ruiz Diaz, Miguel Ángel Ruiz-Ibán. 2015. Exploración y evaluación radiológicade la articulación acromioclavicular. Revista Española de Artroscopia y Cirugía Articular 22:1, 11-17. [Crossref]

12. Alex Vaisman, Ignacio Eduardo Villalón Montenegro, María Jesús Tuca De Diego, Juanjose Valderrama Ronco. 2014. A NovelRadiographic Index for the Diagnosis of Posterior Acromioclavicular Joint Dislocations. The American Journal of Sports Medicine42:1, 112-116. [Crossref]

13. Scott E. Sheehan, Glenn Gaviola, Ari Sacks, Robert Gordon, Lewis L. Shi, Stacy E. Smith. 2013. Traumatic Shoulder Injuries: AForce Mechanism Analysis of Complex Injuries to the Shoulder Girdle and Proximal Humerus. American Journal of Roentgenology201:3, W409-W424. [Abstract] [Full Text] [PDF] [PDF Plus] [Supplemental Material]

14. Mark Tauber. 2013. Management of acute acromioclavicular joint dislocations: current concepts. Archives of Orthopaedic andTrauma Surgery 133:7, 985-995. [Crossref]

15. M. Wellmann, G. da Silva, S. Lichtenberg, P. Magosch, P. Habermeyer. 2013. Instabilitätsmuster beiAkromioklavikulargelenkverletzungen vom Typ Rockwood III. Der Orthopäde 42:4, 271-277. [Crossref]

16. L. Vandenbussche, A. Moraux, X. Demondion, E.-L. Glaude, C. Fontaine, A. Cotten. Traumatismes du membre supérieur829-893. [Crossref]

17. Andrea Donovan. Shoulder and Proximal Humerus 109-139. [Crossref]18. Andrew C. Kim, George Matcuk, Dakshesh Patel, John Itamura, Deborah Forrester, Eric White, Christopher J. Gottsegen. 2012.

Acromioclavicular joint injuries and reconstructions: a review of expected imaging findings and potential complications. EmergencyRadiology 19:5, 399-413. [Crossref]

19. Chye Yew Ng, Emma Kate Smith, Lennard Funk. 2012. Reliability of the traditional classification systems for acromioclavicularjoint injuries by radiography. Shoulder & Elbow 4:4, 266-269. [Crossref]

20. Alexander Di Francesco, Carmine Zoccali, Olivo Colafarina, Renzo Pizzoferrato, Stefano Flamini. 2012. The use of hook platein type III and V acromio-clavicular Rockwood dislocations: Clinical and radiological midterm results and MRI evaluation in 42patients. Injury 43:2, 147-152. [Crossref]

21. Katsumi Takase. 2011. MRI evaluation of coracoclavicular ligament injury in acromioclavicular joint separation. European Journalof Orthopaedic Surgery & Traumatology 21:8, 563-568. [Crossref]

22. Bill Ristevski, Michael D. McKee. Acromioclavicular Joint 323-331. [Crossref]

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23. Ursula Nemec, Gerhard Oberleitner, Stefan F. Nemec, Michael Gruber, Michael Weber, Christian Czerny, Christian R. Krestan.2011. MRI Versus Radiography of Acromioclavicular Joint Dislocation. American Journal of Roentgenology 197:4, 968-973.[Abstract] [Full Text] [PDF] [PDF Plus]

24. Yulia Melenevsky, Corrie M. Yablon, Arun Ramappa, Mary G. Hochman. 2011. Clavicle and acromioclavicular joint injuries: areview of imaging, treatment, and complications. Skeletal Radiology 40:7, 831-842. [Crossref]

25. Radha N. Ekbote, Jason W. Stephenson. 2011. Lower trapezius muscle avulsion from thoracic spinous processes in a patient witha history of trauma. Radiology Case Reports 6:4, 565. [Crossref]

26. Aylin Yucel, Ozge Yilmaz Kusbeci. 2010. Magnetic resonance imaging findings of shoulders in Parkinson's disease. MovementDisorders 25:15, 2524-2530. [Crossref]

27. Stephan Pauly, Christian Gerhardt, Norbert P. Haas, Markus Scheibel. 2009. Prevalence of concomitant intraarticular lesionsin patients treated operatively for high-grade acromioclavicular joint separations. Knee Surgery, Sports Traumatology, Arthroscopy17:5, 513-517. [Crossref]

28. David N. Collins. Disorders of the Acromioclavicular Joint 453-526. [Crossref]29. Nikdokht Farid, Dean Bruce, Christine B. Chung. 2008. Miscellaneous conditions of the shoulder: Anatomical, clinical, and

pictorial review emphasizing potential pitfalls in imaging diagnosis. European Journal of Radiology 68:1, 88-105. [Crossref]30. . The shoulder girdle 1-104. [Crossref]31. Faisal Alyas, Mark Curtis, Cathy Speed, Asif Saifuddin, David Connell. 2008. MR Imaging Appearances of Acromioclavicular

Joint Dislocation. RadioGraphics 28:2, 463-479. [Crossref]32. Philippe Peetrons, Justine P. Bédard. 2007. Acromioclavicular joint injury: Enhanced technique of examination with dynamic

maneuver. Journal of Clinical Ultrasound 35:5, 262-267. [Crossref]33. Angharad Lee, Quamar Bismil, Richard Allom, Jeremy Pike. 2006. Missed type IV AC joint dislocation: A case report. Injury

Extra 37:8, 283-285. [Crossref]34. Pascal Boileau, Matias Villalba, Jean-Yves Héry, Frédéric Balg, Philip Ahrens, Lionel Neyton. 2006. Risk Factors for Recurrence

of Shoulder Instability After Arthroscopic Bankart Repair. The Journal of Bone & Joint Surgery 88:8, 1755-1763. [Crossref]35. Fritz K. Schaefer, Philipp J. Schaefer, Joachim Brossmann, Ralf Erik Hilgert, Martin Heller, Thomas Jahnke. 2006. Experimental

and clinical evaluation of acromioclavicular joint structures with new scan orientations in MRI. European Radiology 16:7,1488-1493. [Crossref]

36. Christian Fialka, Christian Robert Krestan, Paul Stampfl, Klemens Trieb, Seyedhossein Aharinejad, Vilmos Vécsei. 2005.Visualization of Intraarticular Structures of the Acromioclavicular Joint in an Ex Vivo Model Using a Dedicated MRI Protocol.American Journal of Roentgenology 185:5, 1126-1131. [Abstract] [Full Text] [PDF] [PDF Plus]

37. John R Deitch. 2004. Acromioclavicular joint injuries. Current Opinion in Orthopaedics 15:4, 261-266. [Crossref]

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